Columbus and Magellan had it rough. Exploration these days is quite literally an armchair activity, as high-resolution satellite images and tools like Google Earth make it possible for anyone with an Internet connection to pore over the globe with a fine-toothed comb. There are entire online communities devoted to finding and cataloging the most unusual locales worldwide, creating 21st century atlases of minutiae. It isn't just for hobbyists, either  Google Earth has helped scientists find previously unknown ruins and police locate clandestine marijuana fields. Here are 10 of the most unusual discoveries.

Firefox Crop Circles

Google Earth

Maybe alien technology isn't so foreign after all. This Firefox crop circle sprouted up in a cornfield in Oregon, but its origins are no mystery. In 2006, the Oregon State University Linux Users group created the giant logo  spanning more than 45,000 sq. ft.  to celebrate the Web browser's 50 millionth download.